Levels of impairment of sensori-motor functions in children with early brain damage

Sixty-three ambulatory, educable children with early brain damage were tested neurologically, with the WISC, and with supplementary sonsory and perceptual tasks derived from studies of cases of late brain injury. Performance on these latter tasks was also assessed in normal children over a wide range of ages.Early damage seemed to spare elementary sensory function while motor impairment was conspicuous, particularly impairment of the oculomotor system, and the latter correlated with dificient performance on spatial tasks. Performance on a variety of verbal and non-verbal tasks correlated with lateralization of symptoms in the brain-damaged group; a reciprocal pattern emerged depending upon whether the right or left side of their body was predominantly involved.The results suggest that the adult pattern of hemispheric specialization antedates birth and that damage which does not encroach directly on the language zones leaves that pattern intact if somewhat attenuated, particularly in the case of left hemisphere functions. There were in the group of 63 only 12 with right-sided (left hemisphere) neurological signs and only 3 of these were dysphasic. This inequality of lateralizing signs could reflect a sampling bias (childred with right-sided signs may be more language impaired and less “educable”) or some greater invulnerability of the left hemisphere to early damage.